com.paolodragone.util.io.datasets.tsv.TsvDataSetReader.java Source code

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Here is the source code for com.paolodragone.util.io.datasets.tsv.TsvDataSetReader.java

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/*
 * Copyright Paolo Dragone 2014
 *
 * This file is part of WiktionarySemanticNetwork.
 *
 * WiktionarySemanticNetwork is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * WiktionarySemanticNetwork is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with WiktionarySemanticNetwork.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.paolodragone.util.io.datasets.tsv;

import com.paolodragone.util.io.datasets.DataColumn;
import com.paolodragone.util.io.datasets.DataRecord;
import com.paolodragone.util.io.datasets.DataSetReader;
import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;
import org.apache.commons.csv.CSVRecord;

import java.io.Reader;
import java.util.Iterator;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

/**
 * @author Paolo Dragone
 */
public class TsvDataSetReader implements DataSetReader {

    private final CSVFormat format;
    private final DataColumn[] header;
    private CSVParser parser;

    TsvDataSetReader(DataColumn[] header, CSVFormat format) {
        this.format = format;
        this.header = header;
    }

    @Override
    public void open(Reader reader) throws Exception {
        if (!isOpen()) {
            parser = new CSVParser(reader, format);
        }
    }

    @Override
    public boolean isOpen() {
        return parser != null;
    }

    @Override
    public Stream<? extends DataRecord> getRecordStream() {
        if (!isOpen()) {
            throw new IllegalStateException("This reader is not opened.");
        }
        return StreamSupport.stream(spliterator(), false);
    }

    @Override
    public void close() throws Exception {
        if (parser != null) {
            parser.close();
            parser = null;
        }
    }

    @Override
    public Iterator<DataRecord> iterator() {
        if (!isOpen()) {
            throw new IllegalStateException("This reader is not opened.");
        }
        return new TsvDataRecordIterator(parser.iterator());
    }

    private class TsvDataRecordIterator implements Iterator<DataRecord> {

        private final Iterator<CSVRecord> csvRecordIterator;

        public TsvDataRecordIterator(Iterator<CSVRecord> csvRecordIterator) {
            this.csvRecordIterator = csvRecordIterator;
        }

        @Override
        public boolean hasNext() {
            return csvRecordIterator.hasNext();
        }

        @Override
        public DataRecord next() {
            return new TsvDataRecord(csvRecordIterator.next(), header);
        }

        @Override
        public void remove() {
            csvRecordIterator.remove();
        }
    }
}